When lifting a load with a hoist and a sling, it is sometimes desirable or required to tilt the load, such as when removing or installing the engine of a vehicle, which can require changing the attachment of the hoist to the sling.
Ehrhardt U.S. Pat. No. 3,391,957, issued July 9, 1968, discloses a "Universal Hoisting Fixture" in which the central portion of a single sling line is wound on a drum and the free ends of the line are connected to the load to be lifted. The drum can be turned for tilting the load. Prior to lifting the load the loose coils of sling line may become crossed or bind against each other on the frame supporting the drum making it difficult to rotate the drum. In addition, as the drum is rotated the coils of sling line have a tendency to progress toward a side of the frame and can exert substantial side pressure on the frame. Further, only the weight of the load tightening the coils on the drum deters the line from slipping relative to the drum, and in an extreme tilted position the load can slip toward a more horizontal position.
Other types of hoist tackle in which a sling line is wound on a drum are shown in: Caldwell U.S. Pat. No. 2,356,147, issued Aug. 22, 1944, Pridy U.S. Pat. No. 2,617,677, issued Nov. 11, 1952, Morith U.S. Pat. No. 2,620,218, issued Dec. 2, 1952, Young U.S. Pat. No. 3,254,913, issued June 7, 1966, Tattoo et al. GB patent No. 1,576,311, published Oct. 8, 1980, and Khark SU patent No. 1096187, issued June 7, 1984.